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991.
Synthesis of [3]Rotaxanes that Utilize the Catalytic Activity of a Macrocyclic Phenanthroline–Cu Complex: Remarkable Effect of the Length of the Axle Precursor
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Yoshiaki Yamashita Dr. Yuichiro Mutoh Dr. Ryu Yamasaki Prof. Takeshi Kasama Prof. Shinichi Saito 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(5):2139-2145
[3]Rotaxanes, which consist of one macrocyclic phenanthroline compound and two axle components, were prepared by the oxidative dimerization of an alkyne compound with bulky tris[4′‐cyclohexyl‐(1,1′‐biphenyl)‐4‐yl]methyl blocking group. The catalytic activity of a macrocyclic phenanthroline–Cu complex was utilized to thread the two axle components inside the ring. The alkyne compound with chain of 15 or 20 methylene groups gave [3]rotaxanes in high yields, whereas the axle with a chain of six methylene groups afforded a [3]rotaxane in very poor yield. We also examined the effect of the ring size on the synthesis of [3]rotaxanes. [3]Rotaxanes were not isolated when a macrocyclic phenanthroline compound with a smaller ring size was used. 相似文献
992.
Takahiko Masuda Hideaki Hara Yuki Miyamoto Susumu Kuma Itsuo Nakano Chiaki Ohae Noboru Sasao Minoru Tanaka Satoshi Uetake Akihiro Yoshimi Koji Yoshimura Motohiko Yoshimura 《Hyperfine Interactions》2015,230(1-3):73-77
We recently reported an experiment which focused on demonstrating the macro-coherent amplification mechanism. This mechanism, which was proposed for neutrino mass measurements, indicates that a multi-particle emission rate should be amplified by coherence in a suitable medium. Using a para-hydrogen molecule gas target and the adiabatic Raman excitation method, we observed that the two photon emission rate was amplified by a factor of more than 1015 from the spontaneous emission rate. This paper briefly summarizes the previous experimental result and presents the current status and the future prospect. 相似文献
993.
994.
Fast and Efficient Oxidative Cycloreversion Reaction of a π‐Extended Photochromic Terarylene
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Jan Patrick Calupitan Dr. Takuya Nakashima Yuichiro Hashimoto Prof. Tsuyoshi Kawai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(29):10002-10008
We report herein a dramatic improvement in the kinetics and efficiency of an oxidative cycloreversion reaction of photochromic dithiazolylthiazoles. The cycloreversion reaction of a colored isomer of dithiazolylthiazole proceeds not only by photo‐irradiation, but also through chemical oxidation with a net efficiency far exceeding 100 % owing to a chain reaction mechanism. By introducing aromatic groups on the reactive carbon atoms at the ends of a photoreactive 6π system in a dithiazolylthiazole, the net bleaching reaction rates were increased by up to 1300‐fold, and turnover rates increased by two orders of magnitude. Based on a combination of classical kinetic analyses and DFT calculations, we attribute this improvement to acceleration of the rate‐determining step to produce the active species in the chain‐reaction oxidative cycloreversion. 相似文献
995.
996.
U. Tanaka K. Masuda Y. Akimoto K. Koda Y. Ibaraki S. Urabe 《Applied physics. B, Lasers and optics》2012,107(4):907-912
We report a surface electrode trap with a relatively large trap depth (0.6–1.0?eV). The trap electrodes are formed by gold plating an alumina substrate. Calcium ions are trapped approximately 400?μm above the trap surface. We demonstrate micromotion compensation based on parametric resonance for surface electrode traps. Unlike the conventional method based on radio-frequency (rf)–photon correlation in which the wave vector of the laser beam must have a component parallel to the micromotion to be detected, the proposed method is independent of the laser propagation direction. This enables the micromotion component normal to the electrode surface to be detected without increasing the scattered light. 相似文献
997.
Organocatalytic Enantioselective Decarboxylative Reaction of Malonic Acid Half Thioesters with Cyclic N‐Sulfonyl Ketimines by Using N‐Heteroarenesulfonyl Cinchona Alkaloid Amides
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Prof.Dr. Shuichi Nakamura Masahide Sano Ayaka Toda Dr. Daisuke Nakane Prof.Dr. Hideki Masuda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(10):3929-3932
The organocatalytic enantioselective decarboxylative Mannich reaction of malonic acid half thioesters (MAHTs) with cyclic N‐sulfonyl ketimines by using N‐heteroarenesulfonyl cinchona alkaloid amides afforded products with high enantioselectivity. Both enantiomers of the products could be obtained by using pseudoenantiomeric chiral catalysts. The reaction proceeds through a nucleophilic addition of the MAHTs to the ketimines prior to decarboxylation. 相似文献
998.
Promotion of Double‐Duplex Invasion of Peptide Nucleic Acids through Conjugation with Nuclear Localization Signal Peptide
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Dr. Yuichiro Aiba Yuta Honda Prof. Dr. Makoto Komiyama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(10):4021-4026
Pseudo‐complementary peptide nucleic acid (pcPNA), as one of the most widely used synthetic DNA analogues, invades double‐stranded DNA according to Watson–Crick rules to form invasion complexes. This unique mode of DNA recognition induces structural changes at the invasion site and can be used for a range of applications. In this paper, pcPNA is conjugated with a nuclear localization signal (NLS) peptide, and its invading activity is notably promoted both thermodynamically and kinetically. Thus, the double‐duplex invasion complex is formed promptly at low pcPNA concentrations under high salt conditions, where the invasion otherwise never occurs. Furthermore, NLS‐modified pcPNA is successfully employed for site‐selective DNA scission, and the targeted DNA is selectively cleaved under conditions that are not conducive for DNA cutters using unmodified pcPNAs. This strategy of pcPNA modification is expected to be advantageous and promising for a range of in vitro and in vivo applications. 相似文献
999.
Kumamoto Yuichiro Aoyama Michio Hamajima Yasunori Nagai Hisao Yamagata Takeyasu Kawai Yoshimi Oka Eitarou Yamaguchi Atsushi Imai Keiri Murata Akihiko 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(2):1209-1217
Journal of Radioanalytical and Nuclear Chemistry - In 2014, we measured activity concentration of radiocesium in the western North Pacific Ocean. In the north of Kuroshio Front high activity... 相似文献
1000.
In M-estimation under standard asymptotics, the weak convergence combined with the polynomial type large deviation estimate of the associated statistical random field Yoshida (2011) provides us with not only the asymptotic distribution of the associated M-estimator but also the convergence of its moments, the latter playing an important role in theoretical statistics. In this paper, we study the above program for statistical random fields of multiple and also possibly mixedrates type in the sense of Radchenko (2008) where the associated statistical random fields may be nondifferentiable and may fail to be locally asymptotically quadratic. Consequently, a very strong mode of convergence of a wide range of regularized M-estimators is ensured.Our results are applied to regularized estimation of an ergodic diffusion observed at high frequency. 相似文献